Transcatheter repair safe and effective among patients with mitral regurgitation secondary to cardiomyopathy: NEJM

This study randomly assigned patients with heart failure and moderate-to-severe or severe secondary mitral regurgitation. Despite using guideline-directed medical therapy at maximum doses, these patients were symptomatic. These patients were assessed for 5-year efficacy and safety of transcatheter edge-to-edge repair.

The study had two groups: a combo of transcatheter edge-to-edge repair plus receive medical therapy as the device group and medical therapy alone as a control group.

The primary endpoint was all hospitalization for heart failure through 2 years of follow-up. After two years, control group patients could receive the device.

The study summary includes the following points:

• Out of 614 patients, the number of patients in the device and control group were 302 and 312, respectively.
• In the device group and control group, the annualized rate of hospitalization for heart failure through 5 years was 33.1% and 57.2% per year, respectively, with a hazard ratio of 0.53. The all-cause mortality through 5 years was 57.3% and 67.2%, respectively, with a hazard ratio of 0.72.
• The percentage of death or hospitalization for heart failure within five years in the device and control groups was 73.6% and 91.5%, respectively.
• Device-specific adverse events were rare and occurred within the first 30 days after the procedure.

They said that transcatheter edge-to-edge repair of the mitral valve is safe and leads to a lower rate of hospitalization for heart failure and lower all-cause mortality through 5 years of follow-up than medical therapy alone.

For limitations and possible questions, they said that patients and investigators knew the assigned treatment because the trial was not blinded. Regarding withdrawal, it was more in the control group.

They also clarified that there was low usage of recommended drugs (some classes) as part of guideline-directed medical therapy.

The study was funded by Abbott, as acknowledged.

Further reading:

https://www.nejm.org/doi/full/10.1056/NEJMoa2300213